How to create a sprite ???

I have seen in tutorials that how you can create a sprite ,but when I tried to create one like gun ,the white backgroung in the image of the gun is still exist,althought I have turned it to 2D sprite.
I want only the shape of the gun, how I can get it ??

as DThaiPome said you have to use a program that support transparency so cheek this one it’s a vector graphic program aka what ever you maximize or minimize images inside the program no pixels will be lost it’s Alternative to adobe illustrator but it’s free inkscape

how to add transparency to a image with Paint.net.

Step 1 : Download and install Paint Dot Net from Paint.NET - Download 6.6 Mb
Step 2 : Start Paint Dot Net.
Step 3 : Open your image “Gun Sprite”, Click File → Open. then select the image.
Step 4 : Select ‘Magic Wand’ from ‘Tools’ Box.
Step 5 : Set tolerance to 0% (At the toolbar).
Step 6 : With ‘Magic Wand’ Selected, Click on white background that you don’t need.
Step 7 : Press ‘Delete’ Button on your keyboard. or Click Edit → Erase Selection.
Step 8 : Now Click File → Save As.
Step 9 : Select ‘Save as type to PNG’.(JPGs and BMPs cannot contain Transparency)
Step 10 : Put saved file into your projects ‘Assets’ Directory, Or any subdirectory.

Now you have a Gun Sprite with a Transparent Background.

Thank you guys , I have solved by Adobe Fireworks ^^

I want you to answer another question ,please

Hello, I’m not sure which program you are using to create your sprites.

You could use Photoshop (download a trial), export, to a .PNG (32)

PNG’s preserve transparency of the artwork.
If you dont want to use the Export option there is always save for web, you can save the PNG from there.

http://www.adobe.com/uk/products/photoshop.html?sdid=KKQPG&mv=search&s_kwcid=AL!3085!3!188947262099!b!!g!!photoshop%20free&ef_id=WQrO4AAAAG36Kwjx:20170504064904:s

Let me know if you have any other questions.